Piston ring



Sept. 4, 1928. 1,682,886

S. J. COCKS ET AL PISTON RING Filed May 17, 1926 INVE'NTORS SIDNEY HN COCKS RAYMON awnv BROWNING ATTORNEYS alenle Sept... l28.

lllllll lEW "l'UHhl UUULW AND a one an nnowurue. or vnncouvnn, nnrrran UULUMBM, EMMA.

llppllcation riled May ll", ltlhll. fierlal llo. 1.093%.

Uur invention relates to improvements in piston rings, the objects of which are to provide means whereby the periphery of the rin is in resilient contact with the cylinder walls, and the upper and lower faces of the ring are in permanent contact with the sides of the groove in :which the ring is fitted to the piston, whereby the said surface contacts are unimpaired by wear throughout the life of the ring.

The invention consists essentially of a spiral forming a cylindrical body of larger diaeter than the piston to which it is fitted, in which the end faces are parallel to each other and at a tangent to the ion itudinal axis of the cylinder in which it is tted, as will be ore fully described in the following specification, in which big. 1 is a general view of the ring fitted to a iston.

ig. 2 is a fractionated sectional view of .the ring and the piston to which it is fitted.

Fi 3 is a fractionated sectional view of the piston in the cylinder showing the position assumed by the ring when fitted in working position.

In the drawings lilre characters of reference indicate corresponding parts in each figure.

e numeral 1 indicates a piston having side walls 2 which are provided with a peripheral groove 3 of a suitable depth. The groove is provided with parallel upper and lower faces 4 and 5 which are disposed at a tangent to'the longitudinal axis of the piston l. The numeral Gindicates one of the side walls of the cylinder into which thepiston is fitted.

'lhe numeral 7 indicates a cylindrical piston ring preferably formed from a cast iron sleeve which is cut in spiral form as shown in Figure l and is of such a size as to require it to be compressed or wound to a smaller diameter when inserting it into the a cylinder. .lhe upper and lower faces 8 and 9 of the ring are turned arallel to each other and at an angle coinciding with that of the upper and lower faces 4 and of the groove 3 in the piston. The total peripheral face excess of the length of the groove 3 so that it is necessary after the ring has been passed over the piston head and as the ring is worked into the cylinder to tighten up the spiral to increase its number of turns beyond the nor- 1 nial. ln this process of tightening the spiral, which will naturall be ed'ected to a greater extent at one end t ereof than at the other such as is shown in Figure 3, the tightly compressed lowerend .coils of the spiral will be disposed closer to the axis of the piston as at 10, than the upper coils thereof. This tightening of the spiral and consequent increase in the total length of the ring will cause the lower end 9 to move downwardly of the angle 5 towards the axis of the piston maintaining at all positions a gas tight contact between the peripher of the ring 7 and the side walls 6 of the cy inder and also between the faces. 8 and 9 of the ring and the faces a and 5 of the groove 3.

As wear talres place between the lin and the cylinder side walls the inherent resi ience of the metal of the ring will cause the spiral to gradually expand, corres ondingly re ducing the number of turns total compressed length. This expansion will cause the lower end coils 10 to expand more rapidly than the others and in so doing will cause the lower face 9 of the rin tomove uplwards along the lower face 5 of t e groove w ile still maintaining the parts in gastight contact. I

What we claim as our invention is:

1. A pistonassembly comprising a piston having a peripheral groove, said groove having OPPOSIIIO end faces parallel to each other and incline with respect to the longitudinal axis of the piston,,a spiral ring to the piston having inclined end faces parallel. to each other and adapted to make gas tight contact with the end faces of the groove.

2. A piston ring comprising a cylindrical body formed of a plurality of spiral coils adapted to be pressed into intimate contact with each other the end faces of the body being parallel to each other and inclined with respect to the longitudinal axis of the body. 3. The combination with a piston formed lellglh of the g 7 is equal to g y in with an annular groove having the-side walls erein and its thereof dis osed in parallel relation toone faces adapted to make gas tight contact with another an inclined with respect to the lonthe side walls of the groove. gitudinal axis of the piston, of a s rin metal Dated at Vancouver, B. C. this 4th day of 1 strip coiled spirally into 0 lin rica form May, 1926.

and afiording a longitudina y and circumferentially expansive iston ring seated in SIDNEY JOHN COCKS. said groove and provi ed with inclined end RAYMOND-EDWIN BROWNING. 

